1. Technical Field
Various embodiments relate generally to wireless communications and more particularly to communication devices that employ a transceiver front end.
2. Description of Related Art
A communication transceiver typically performs two-way, or bidirectional, communications through one or more communication links. For wireless communication links, the transceiver often transmits and receives over a shared antenna or antenna array. A typical transceiver front end includes a transmission amplifier, such as a power amplifier (PA) with enough drive capability to generate strong transmitter waveforms, and a reception/RF amplifier, such as a low noise amplifier (LNA) with suitable fidelity to increase the sensitivity of the receiver by amplifying weak signals with minimal noise contamination, such that the signals are above the noise level of succeeding signal processing stages. The transmission amplifier and the reception amplifier are often individually impedance-matched (especially at higher frequencies) to a shared antenna so that maximum power is transferred to/from the antenna. In order to facilitate such impedance matching, various mechanisms may be employed to selectively couple the transmission amplifier and the reception amplifier to the shared antenna during respective transmit and receive modes of operation.
Such mechanisms often depend on characteristics of the shared antenna (or other medium) and the design of the communication system. One common technique used at radio frequencies (RF) involves transmit/receive (or T/R) switches. In this technique, the transmission amplifier and the reception amplifier are selectively coupled to the shared antenna via one or more T/R switches. Major requirements for a traditional T/R switch include low insertion loss, high power handling capability, high linearity, good isolation and reliability.